The influence of adiposity and acute exercise on circulating hepatokines in normal weight and overweight/obese men

Hepatokines are liver-secreted proteins with potential to influence glucose regulation and other metabolic parameters. This study investigated differences in adiposity status on five novel hepatokines and characterised their response to acute moderate-intensity exercise in groups of normal weight and overweight/obese men. Twenty-two men were recruited into normal weight and overweight/obese groups (BMI: 18.5 to 24.9 and 25.0 to 34.9 kg∙m-2). Each completed two experimental trials, exercise and control. During exercise trials, participants performed 60 min of moderate-intensity treadmill exercise (~60% V̇O2 peak) and then rested for 6 h. Participants rested throughout control trials. Circulating fibroblast growth factor-21 (FGF21), follistatin, leukocyte cell-derived chemotaxin 2 (LECT2), fetuin-A and selenoprotein-P (SeP) were measured throughout. Fasted (resting) FGF21 and LECT2 were higher in overweight/obese individuals (129% and 55%; P ≤ 0.01) and correlated with indices of adiposity and insulin resistance; whereas circulating follistatin was lower in overweight/obese individuals throughout trial days (17%, P < 0.05). In both groups, circulating concentrations of FGF21 and follistatin were transiently elevated after exercise for up to 6 h (P ≤ 0.02). Circulating fetuin-A and SeP were no different between groups (P ≥ 0.19) and, along with LECT2, were unaffected by exercise (P ≥ 0.06). These findings show that increased adiposity is associated with a modified hepatokine profile, which may represent a novel mechanism linking excess adiposity to metabolic health. Furthermore, acute perturbations in circulating FGF21 and follistatin after exercise may contribute to the health benefits of an active lifestyle.